The fall was a sign that companies were choosing to drill “only the most competitive and profitable” wells, said Ross Dornan, market intelligence manager at the trade body.

The industry warned againsta tax grab in the budget, a prospect that has been raised recently. High oil prices mean the sector is set to generate £10bn in free cash flow this year, a level not seen since 2010, but the Treasury’s take is expected to be down a quarter on 2010, because of tax changes.

Dornan said Treasury ministers had reassured him that the government was “committed to fiscal stability.” He added: “Industry and the Treasury can’t be complacent in this area.”